Does work done depend upon the velocity of the body?

$(a)$ Can a body have energy without having momentum? Explain.
$(b)$ Can a body have momentum without having energy? Explain.

$A$ light and a heavy body have the same momentum. Which one will have greater kinetic energy?

Four persons jointly lift a $250 \,kg$ box to a height of $1 \,m$ and hold it.
$(a)$ Calculate the work done by the persons in lifting the box.
$(b)$ How much work do they do just holding it?
$(c)$ Why do they get tired while holding it? $(g = 10 \,m/s^2)$

State whether the following statement is true or false:
When a body falls on the ground and stops,the principle of conservation of energy is violated.

$(i)$ Define power. Mention its $SI$ unit.
$(ii)$ $A$ boy of mass $50 \, kg$ runs up a staircase of $40$ steps in $8 \, s$. If the height of each step is $15 \, cm$,find his power. (Given,$g = 10 \, m \, s^{-2}$)